In microscopy, what is the function of a coverslip?

The function of a coverslip in microscopy is to provide a flat surface for observation. When preparing a slide for viewing under a microscope, the specimen is often placed between the slide and the coverslip. This flat surface is important because it helps achieve a uniform thickness of the specimen, which allows for better focus and clarity when viewing the specimen under magnification.

Additionally, the coverslip can help to reduce the amount of light diffraction and improve the quality of the images observed. It also creates a stable environment that minimizes disturbances to the specimen during examination. While coverslips can help in other ways, such as preventing contamination and limiting the evaporation of liquids in the case of wet mounts, their primary role is to offer a flat, even surface that ensures effective viewing through the microscope.